Pohang-Guryongpo, December 20

Bird News from Nial Moores and Jason Loghry

A day spent “gulling” under largely clear skies with the westerly wind increasing from light to moderate and temperatures rising to a mild 7C or 8C before falling sharply again in the evening. Although conditions were poor for finding alcids (and only one Ancient Murrelet was seen, by JL only), species of note included: a neck-banded Whooper Swan on the river in Pohang (too far to read, but white numbering on red); two American and 3+ Asiatic White-winged Scoters; a dozen or more Harlequin Duck; c. 50 loons (mostly Red-throated with at least one Arctic); 500+ Great Crested Grebe; one White-tailed Eagle (in Pohang); and probably 10+ Light-vented Bulbul. Our main focus throughout the day, however, was on gulls, and at least 11 species were found along with one Caspian-type gull, a couple of dark First Calendar-years that suggested smithsonianus, and several really puzzling individuals (two of which are included here).

Gulls seen during the day, in most cases not counted but estimated, included:

1. Black-legged Kittiwake Rissa tridactyla. At least 250 were seen in one scan, and likely many more were missed, mixed in with a huge feeding flock of Black-headed Gulls.

Black-legged Kittiwake Rissa tridactyla, © Jason Loghry
2. Black-headed Gull Chroicocephalus ridibundus. Easily the most numerous bird of the day, with a huge flock feeding off from Daebo and several roosts of between 3,000 and 5,000 strung along the eastern side of the peninsula. Although only a few quick, coarse counts were made probably ~25,000 were seen in total. Personally (for both NM and JL), this is easily the highest number of Black-headed Gull seen at any site in the ROK and most likely anywhere. For greater context, this estimate is three times higher than any count given in Park Jin-Young’s 2002 thesis (8,000 in January 2001, along perhaps the same part of the coast); and is about the same as the total number counted nationwide in the MOE winter census in 2007, 2010 and 2013.

Black-headed Gull Chroicocephalus ridibundus, © Jason Loghry

Adult Black-headed Gull Chroicocephalus ridibundus, © Jason Loghry

First-winter Black-headed Gull Chroicocephalus ridibundus, © Nial Moores

First-winter Black-headed Gull Chroicocephalus ridibundus, © Nial Moores
3. Saunders’s Gull Chroicocephalus saundersi. Two or three were in the river in Pohang.
4. Black-tailed Gull Larus crassirostris. Probably c. 500 were seen during the day, including a few still in largely juvenile plumage.

Black-tailed Gull Larus crassirostris, © Nial Moores
5. Common Gull Larus canus. Probably 100-150 were seen during the day.
6. Glaucous-winged Gull Larus glaucescens. One adult and three First Calendar-years. None of the First Calendar-years were as dark as the one seen in Gangneung on December 6^th.

Adult Glaucous-winged Gull Larus glaucescens, © Nial Moores

First Calendar-year Glaucous-winged Gull Larus glaucescens, © Nial Moores

First Calendar-year Glaucous-winged Gull Larus glaucescens, © Nial Moores
7. Glaucous Gull Larus hyperboreus. Seven or eight adults were seen along the west coast of the peninsula; none were seen along the east coast; and puzzlingly no First-winters were seen during the day.

Glaucous Gull Larus hyperboreus with Slaty-backed Gull, © Nial Moores
8. Vega Gull Larus vegae. At least 800, showing the predictably huge range of characters “typical” of this gull, with dark and pale First-winters; huge and much smaller-looking adults; and adults with cloudy-grey tones to the upperpart grey, and a few which looked much darker. No birulai types were noted, however.

Adult Vega Gull Larus vegae, © Nial Moores

Small-end Vega Gull Larus vegae, © Nial Moores

First winter Vega Gull Larus vegae, © Nial Moores
9. Mongolian Gull Larus mongolicus. Probably three white-headed adults and ten or so First-winters were seen during the day (showing a great range in size, but with the First-winters sharing the same pale-grey scapulars and mantle, with darker anchors or bars; worn tertials; and white-looking head, some with a trace of streaking still on the crown, others much cleaner-looking already).

First winterMongolian Gull Larus mongolicus, © Nial Moores

Small-end First winterMongolian Gull Larus mongolicus, © Nial Moores
10. Slaty-backed Gull Larus schistisagus. Probably 300-400 were seen during the day, with non-adults displaying a great range in plumage.

First winter Slaty-backed Gull Larus schistisagus, © Nial Moores

Grey-toned First winterSlaty-backed Gull Larus schistisagus, © Nial Moores

Second winter Slaty-backed Gull Larus schistisagus, © Nial Moores

Second winter Slaty-backed Gull Larus schistisagus, © Nial Moores
11. Taimyr Gull Larus heuglini taimyrensis. Small numbers were present in all of the main gull roosts, especially those close to Guryongpo town, and probably 30-40 were seen during the day. Of note, several adults were still in active primary moult (already completed in the vast majority of vegae), while several First-winters were instead rather well-advanced, with much white coming through on the head and strongly-scaled upperparts.

Second winter Taimyr Gull Larus heuglini taimyrensis, © Nial Moores
12. Caspian-type Gull Larus cahninnans / mongolicus / barabensis. One (gorgeous) adult was watched well in excellent light. The identification of birds like this is massively complicated by a poor understanding of the appearance of eastern Caspian Gull; probable hybridization in the east of the range of cachinnans (where it is believed that it might meet barabensis and might also meet mongolicus etc.); and confusion with one or more populations of mongolicus. Identification as cachinnans, barabensis or mongolicus is strongly suggested in mid-winter by its gleaming white head and limited streaking, confined to light streaks on the nape. The bird appeared to be a little smaller than adjacent Vegas, suggesting it was perhaps a female. Separation from mongolicus was suggested by the upperpart grey tone (slightly paler than Vega: many mongolicus are slightly and some rather darker); odd, narrow “pear-shaped” head; longish-looking bill (especially if a female) with narrow elongated slit; puffed-full chest; thinnish-looking legs; and very long primary projection. The bill was also rather brightly coloured for a non-breeding mongolicus, and showed less black than might be expected, with a more obvious red gape line, while the legs were on the pale side. Separation from barabensis was based on its too-pale upperpart grey tones; the lack of contrast on the underwing between the wing coverts and the flight feathers; and bare part coloration. Problems with identification as a cachinnans appear to include the colour of the oribital ring (clearly red, not orange as indicated by Malling Olsen’s book: though multiple images of Caspian Gull from the east of the range in Azerbaijan have similarly-coloured orbitals: see http://chrisgibbins-gullsbirds.blogspot.kr/2012/08/adult-eastern-caspian-gulls-from.html ); the paleness of the eye, with limited darker speckling (though this too is shown by some); the suspected pattern on some of the primaries, including the amount of black on what is visible of P10 (even though eastern Caspian are often said to show less white and more black than western birds); and perhaps, most importantly, bill length and fullness of the head and rear of the crown combined with its lack of a long-necked look during the observation: all less extreme-looking than many cachinnans within their known breeding range. This bird therefore fell in between what might be expected of mongolicus, cachinnans and barabensis.

Caspian type Gull, © Nial Moores

Caspian type Gull with Vega Gull, © Nial Moores

Caspian type Gull, © Nial Moores

Caspian type Gull, © Nial Moores
13. Dark First Calendar-year. A strikingly attractive “hot chocolate-colored” gull, with a Lesser Black-backed type face mask and long-looking primary projection. More or less in juvenile plumage, it had a heavily barred skua-like uppertail coverts and rump (with five or six complete bars, fading out across a white-based central rump) and also an apparently all dark-tail (just with faint markings towards the base of the outer tail feathers), both features suggesting a North American origin, as not typical of e.g. vegae or taimyrensis. However, the bird looked quite attenuated, and the bill was too solidly dark and the head too washed with brown for what might be expected of smithsonianus. And how to interpret several blackish centres to some of the upper scapulars? Comments, as always, are welcome.

Dark First Calendar year, © Nial Moores

Dark First Calendar year, © Nial Moores
14. Vega-type. An especially slim-billed bird which showed unusually extensive soft-grey on the upperparts for First-winter Vega. Comments, as always, are welcome.
    

    Vega type, © Nial Moores
    

    Vega type, © Nial Moores